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Words with the prefix un-

un- means “not; reverse of”, from Old English.

15 examples of the prefix un-

  1. unhappyun- + happynot happy
  2. unkindun- + kindnot kind
  3. unsafeun- + safenot safe
  4. unfairun- + fairnot fair
  5. unlockun- + lockreverse the locking of
  6. unclearun- + clearnot clear
  7. unpackun- + packreverse the packing of
  8. unusualun- + usualnot usual
  9. unawareun- + awarenot aware
  10. undoun- + doreverse what was done
  11. unwrapun- + wrapreverse the wrapping of
  12. unravelun- + ravelreverse tangled or woven state
  13. unprecedentedun- + precedentedhaving no earlier example
  14. unscrupulousun- + scrupulousnot having moral principles
  15. unequivocalun- + equivocalnot ambiguous or doubtful

How un- works

The prefix 'un-' attaches to adjectives to mean 'not' (unhappy) and to verbs to mean 'reverse the action' (unlock), without changing the part of speech. Unlike the Latin-derived 'in-', 'un-' is native English and never assimilates its spelling to match the following consonant.

Watch out: Words like 'uncle,' 'under,' 'until,' and 'unless' begin with 'un' but do not contain the prefix—they are unrelated roots where 'un' is simply part of the word's original form.

To see prefixes combine with other parts, try the word dissector and root builder, or test yourself in the vocabulary quiz.

Other common prefixes

Questions people ask

What does the prefix un- mean?

un- means “not; reverse of”. It comes from Old English. The prefix 'un-' attaches to adjectives to mean 'not' (unhappy) and to verbs to mean 'reverse the action' (unlock), without changing the part of speech. Unlike the Latin-derived 'in-', 'un-' is native English and never assimilates its spelling to match the following consonant.

What are some examples of words with the prefix un-?

unhappy, unkind, unsafe, unfair, unlock, unclear, unpack, unusual. The full list of 15 examples, with what each one literally means, is above.

Which words look like they have the prefix un- but don’t?

Words like 'uncle,' 'under,' 'until,' and 'unless' begin with 'un' but do not contain the prefix—they are unrelated roots where 'un' is simply part of the word's original form.

What is a prefix?

A prefix is a word part added to the front of a base word or root to change its meaning, like un- in unhappy or re- in rewrite. It does not usually change the part of speech.